The Rolling Theorum is an equation used in current day mathematics. It can be used to find out a large amount of information about geometry when reduced properly (cylinders, specifically, hence the name "Rolling Theorum.")
This equation must be solved for y where x = Z||R and is as follows:

y = ((R²I²CK)/RI) + (2X)/((BA)(R²)(EL))

so, we have to start by dividing the left side of the plus sign. Which leaves us with..

y = (RICK) + (2X)/((BA)(R²)(EL))

Next, we come to the R², which is (RR)

y = (RICK) + (2X)/((BA)(RR)(EL))

And to make it easier to read, we'll leave it as R²

y = (RICK) + (2X)/(BAR²EL)

Now we come to the 2X. We said earlier that it was equal to Z || R, which means Z or R. So let's plug this in..

y = (RICK) + (2(Z || R))/(BAR²EL)

Now, any StarFox fan will recognize this as a Barrel Roll, as 2 times Z or R is a Barrel Roll.

y = (RICK) + (BARREL ROLL)/(BAR²EL)

Simplify BARREL..

y = (RICK) + (BAR²EL ROLL)/(BAR²EL)

divide what's on the right side of the plus sign..

y = RICK + ROLL

AND THERE YOU HAVE IT. Y = RICK ROLL. AND THIS IS TRUELY WHY IT IS CALLED THE ROLLING THEORUM.

"DAMNIT DUDE, I got Rick Roll'd from The Rolling Theorum today!"
"I can use the Rolling Theorum to determine the Length of this Cylinder"